Regular expression : non capturing groups are faster ?

candide candide at free.invalid
Tue Jan 3 09:50:45 EST 2012

Le 03/01/2012 12:56, Devin Jeanpierre a écrit :
>> The second assertion sounds more likely. It seems very odd that Python and
>> Perl implementations are divergent on this point. Any opinion ?
> The Python documentation oversimplifies.

You meant Perl Documentation, didn't you ?

It's a commun opinion that non-capturing groups have a price (minor), 
for instance Jan Goyvaerts, a well known regular expression guru, 
refering to Python code, tells :

non-capturing groups (...)  offer (slightly) better performance as the 
regex engine doesn't have to keep track of the text matched by 
non-capturing groups.

[link is there :]

It seems Javascript performs better respect to non-capturing groups :

The same for java :
(no benchmarks).

For my part, Python tests didn't show any kind of significative penality.

More information about the Python-list mailing list